The first bird wake

Using the first particle image velocimetry system at the animal flight lab, we succeeded in capturing the aerodynamic wake dynamics behind a freely flying thrush nightingale across its entire rage of natural flight speeds. Previous studies had measured wakes behind birds only at single speeds (a pigeon and a jackdaw at a low speed of 2.5 m/s and a kestrel at a medium speed of 7 m/s).

In our study, the evolution of the wake across speeds was captured, showing that birds do not use different so called 'gaits' at different flight speeds as in terrestrial locomotion, but that the wake changes gradually when accelerating from low flight speeds up to the maximum flight speed.

Individual consecutive panels with particle image velocimetry (PIV) data are organized to represent a full wing stroke and sorted on the wing position covered by the laser sheet.